1. Field of the Invention
The present invention relates to a recording apparatus for recording on a recording medium using a recording means, and a method for manufacturing a recorded product by the recording apparatus.
2. Related Background Art
Heretofore, recording apparatuses using a variety of image forming means have been put to practical use. Particularly regarding full-colored image forming means, an ink jet recording apparatus is attracting public attention. This is because the ink jet recording apparatus discharges ink as liquid drops through a discharge port of a recording head for performing dot recording and has advantages in composition and running cost, etc. Typically, in this recording method, a recording head having a row of discharge port(s) with a predetermined width (approximately 16 mm) is applied to scan a recording medium relatively and sequentially in the longitudinal and lateral directions for recording and printing.
In such a type of recording apparatus, the gap between the recording head and the recording material, i.e. recording medium, is set to an optimum value, which is kept unchanged during the recording operation.
As a typical example of a dyeing recording apparatus which is further an example of the above-mentioned recording apparatus, a textile printing apparatus will now be described.
As a conventionally representative textile printing apparatus, there has been known a type using a silk-screen textile printing method in which the printing operation is directly applied on cloths using silk-screen printing. In a screen textile printing method, a screen form is made for each color of an original image to be printed and the ink is directly transferred through the texture of silk to cloths made of cotton, silk and others.
However, such a screen textile printing method has such disadvantages as requiring a significant number of processes and time for making screen forms, and complicated labor for blending inks of various colors needed for printing and for alignment of the screen forms. In addition, the apparatus is basically large-sized, so the more the number of colors to be used, the larger the space needed for installation of the apparatus. Moreover, a storage space for the screen forms must be kept separately.
To overcome such disadvantages, there has been known a technique to print directly on the cloths, i.e. a printing member by the ink jet recording method in which particulates of inks are blown out for forming an image. Further, as a systematized version of this technique, it is possible to read the original image by a reader into a computer for processing the image in a variety of ways, so as to subsequently supply the recording signals to the recording section of the ink jet for the printing process.
According to such a technique, since no screen form is necessary to perform screen textile printing, the processes and time until the printing process can be significantly reduced, enabling small-packaging of the apparatus. Further, the image data for the printing can be stored in a tape, a floppy disk or an optical disc medium, with an excellent keeping and storing property. In addition, processes such as color change, layout change, scale-up/down can be easily applied on the original image.
There are a variety of requirements for the recording medium. In addition to a paper being a typical recording medium and a transparent film used for OHP (Over Head Projector) (e.g. OHP sheet), in recent years a long staple processed paper and a fabric have been required to be used. Then, when recording operation is applied to such a recording material comprising long staple by an ink jet recording apparatus, since the set value of a gap between the recording head and the recording medium is typically so small as 0.5-1 mm, there has been a disadvantage that the recording head absorbs the ink just after it is recorded and the extended recording medium and the recording head are rubbed against each other, thereby blurring the recorded image so as to degrade the image quality.
Further, the similar blurring would also occur when the recording medium is crumpled and floated, and in the worst case an end of the recording medium and the recording head would collide to break or damage the recording material. Particularly when a film or a fabric is used as the recording medium, the intensity of the recording medium is significantly high. Therefore, any collision of the recording medium end and the recording head would seriously and undesirably affect the recording head carrying mechanism so as to lower the positional accuracy between the recording head and the recording medium.
It is therefore an object of this invention to provide a recording apparatus which is capable of preventing any rubbing of a recording medium and a recording head by a simple structure and preventing the lowering of the recorded image quality and an undesirable effect to the apparatus.
Further, the technique of the present invention would contribute to overcome a problem due to the difference of the thickness of the recording medium. Such a problem occurring when image data is recorded onto cloths as a recording medium by the above-mentioned dyeing apparatus, as an example, will be now described.
As shown in FIGS. 7A, 7B and 7C, when the thickness of cloths are different as 1.sub.0, 1.sub.1, 1.sub.2 (1.sub.0 &lt;1.sub.1 &lt;1.sub.2), the distance between the surface of the cloths 60 and a discharging aperture 29 of the recording head 10 when the cloths 60 are attached to the conveying belt 37 and ink drops are ejected onto the cloths 60 by the recording head 10 would be varied as d.sub.0, d.sub.1, d.sub.2 (d.sub.0 &gt;d.sub.1 &gt;d.sub.2), respectively. As a result, the deviate amount t, shown in FIG. 9, of the ink drops discharged from the recording head 10 to the recording dot-reaching position from an ideal dot-reaching position on the cloths 60 would be proportional to the distance d between the surface of the cloths 60 and the discharge port 29 of the recording head 10. When the distance between the cloths and the recording head exceeds a distance d.sub.0 such that the recorded dot reaching deviated amount becomes greater than the critical recording dot reaching deviated amount t.sub.0 (.mu.m), undesirable white streaks out of the tolerance due to the recorded dot reaching deviation would appear, seriously degrading the recording image quality.
On the contrary, when the distance between the surface of the cloths 60 and the discharge port 29 of the recording head 10 becomes too small, although the deviated amount t (.mu.m) of the reached dot becomes small, the fabric system projecting to the surface of the cloths would contact the discharge port 29 of the recording head 10, so as to disturb ejection of the ink drops correctly from the nozzle of the recording head 10.